Oxidation is responsible for a number of degradative reactions in biological products, resulting in shortened shelf life, loss in color intensity, generation of unpleasant flavors and odors, loss in nutritional quality, and changes in physical characteristics. Such oxidation can also affect the bioactivity of natural components in consumer products such as anti-aging skin creams. The key components involved in oxidation of packaged products include free radicals to initiate the oxidative process, trace metals to catalyze the reaction, and oxygen to propagate the reaction, inhibiting any of these components can reduce the potential for oxidation and resulting product loss.
One strategy for reducing oxidation of packaged products has been to blend radical scavengers such as phenolic compounds, occurring naturally in many essential oils, into the packaging material. The method is typically quite costly and the resulting packaging materials suffer from poor stability both during the manufacturing process and storing period. Further, by incorporating the antioxidant throughout the packaging material, its bulk material properties can be adversely impacted.
Another strategy for reducing oxidation of packaged products has been to add metal chelators such as ethylenediamine tetraacetic acid (EDTA) or citric acid directly to the food product. Likewise, synthetic antioxidants such as butylatedhydroxytoluene (BHT) or butylatedhydroxyanisole (BHA) or natural free radical scavengers have been added directly to food products. Adding such chelators and antioxidants in the product formulation destroys the integrity of the food substance as an “all natural” product. In the case of natural free radical scavengers, such additions to foods are only moderately effective at inhibiting oxidation, are high in cost and have low stability.
Another strategy for reducing oxidation of packaged products has been to include an oxygen absorbing sachet within the package to reduce the oxygen content. Such sachets are inefficient at inhibiting oxidation, are not suitable for use in liquid products and require complicated packaging equipment.
There is a need for methods and materials that inhibit oxidation and other forms of degradation of biological and chemical products without the need to include additives in the product formulations.